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Tomatobro

Geminids been and gone?

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My automated meteor system alerted me just after 16:00 hours of a very high count which has now died away to background. The high count lasted just over an hour. Anyone else see this?  I have not done a detail check of the data yet but it looks to be around 160 events over that period.

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Mine's going really strong just now.  Here's my December heatmap up to 21-22 UTC tonight.

image.png.665b0646c9a6c8a399a4c9b93fd0cc61.png

These are data unfiltered, but watching the Spectrum Lab screen over the last several minutes there are a number of strikes that are not being recorded, possibly because they don't have a large enough initial Doppler or are too weak.  Here for example:

image.png.192226319a9e32d502c01c7b660b91cd.png

Two weak strikes, the first looking like noise the the script and not recorded; the second, looking similar visually, but maybe slightly stronger.

At other times, I'm getting multiple strikes per minute:

image.png.90f22b4b82e1a691c7d56bef34a256cf.png

Based on previous evenings, I expect a small reduction in count over the next few hours, followed by a second peak some time between 4am and 7am.

I doubt I'll have enough time to analyse the data from overnight before heading out to work in the morning, but will try to make time tomorrow evening to update.

Richard

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An update on yesterdays data.

My meteor detection rig shows detections pretty much in line with expectations.  A sharp peak occurred for me between  2100 and 2200 UTC on the evening of the 13th, with a second, broader peak between 0300 and 0800 on the morning of the 14th.  By this evening, detection rates have returned to background rates.

Maximum hourly rates (approximates to ZHR) peaked at a little over 100, which is similar with predictions for the Geminids.

image.png.62a9bb27cd06d21cd5cde86618d77850.png

A decent event for me with significant numbers of incoming strikes over several hours.

Richard

 

 

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Thanks for publishing your data. When I get a chance I will compare with mine.

Unfortunately I forgot to turn off the internet link and windows did an update which resulted in a loss of the automated data but I do have screen recordings (15.5 gb) to look through and do a manual count.

 

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On 14/12/2018 at 22:36, BiggarDigger said:

An update on yesterdays data.

My meteor detection rig shows detections pretty much in line with expectations.  A sharp peak occurred for me between  2100 and 2200 UTC on the evening of the 13th, with a second, broader peak between 0300 and 0800 on the morning of the 14th.  By this evening, detection rates have returned to background rates.

Maximum hourly rates (approximates to ZHR) peaked at a little over 100, which is similar with predictions for the Geminids.

image.png.62a9bb27cd06d21cd5cde86618d77850.png

A decent event for me with significant numbers of incoming strikes over several hours.


 

 

 

Richard

Hi, question here: what do the number of events mean. They depend on the amount of sky you cover, as well as on the radio emitter (you use GRAVES I presume). The predictions are the visually observable. You can normalize your results some way?

cheers Hans

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Hi. These are indeed radar reflections from ionised trails left by Meteors using Graves radar. Reception will vary depending upon equipment and location. One of our club members uses Identical equipment to mine and we are separated by 10 miles and we cannot get traces to match 100%.

There is a website that shows four listening stations at once and  they do not match. http://www.merriott-astro.co.uk

select the 2D option at the top of the screen. the traces are updated every 30 seconds

 

 

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On 24/12/2018 at 15:07, HansW said:

Richard

Hi, question here: what do the number of events mean. They depend on the amount of sky you cover, as well as on the radio emitter (you use GRAVES I presume). The predictions are the visually observable. You can normalize your results some way?

cheers Hans

Hello Hans, welcome to SGL.

The number of events shown in the screen grab are simply the number of strikes recorded per hour by my detection system.  There is no normalisation of that data performed in this presentation.  Perhaps normalisation to a rolling arithmetic mean would be interesting, though it would be difficult to define a normalisation window which is representative of background rates - as you can see there is significant variation in background rates.

Yes, the detection rate will, in theory, depend on the magnitude of common volume of sky illuminated by the receiver and transmitter.  In practice, since the transmitter is the GRAVES Space Radar near Dijon and my range to that is close to the maximum for forward scatter from the rear lobes, a change to the beamwidth of my receive antenna may not make much difference.  As range to the radar decreases, there is scope for experimentation with the common volume.

There are reasonable predictions for most regular meteor showers, which is what makes the data recorded so interesting.  It allows a comparison to be made with those predictions.  However, it would be very difficult, as Tomatobro observed, to fully correlate a set of data between two receiving stations.  Occasionally, it may be possible to correlate a visual meteor with a radio detection, but at my range to the transmitter, this becomes much more difficult because my radio detections represent incoming meteors that would be visually close to the horizon.

There are a number of discussions here which will give more background information, but feel free to ask if you have any questions.

 

Richard

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Thanks. I saw a Dutch website (hemel.waarnemen.com) that gave similar numbers for the visual observation of Geminids. That the normalisation factor between your radio and visual is about 1, is thus accidental. 

The observation of Tomatobro means that one can learn about the location and direction of the meteoroids by finding coicident observation. Then the  reflection cone must be rather sharp (Here I base myself on a German article by prof. Klaus von der Heyden, DJ5HG and an English article by Wolgang Kaufmann, which you probably know about).

Hans

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